The esters of 2-ethylhexanol, especially the phthalate, are among the most commonly used plasticizers. The alcohol is obtainable by, for example, subjecting propene to hydroformylation, dimerizing the resulting butanal by the aldol reaction, a term which is used throughout this specification, including the claims, as including the subsequent dehydration to an unsaturated aldehyde, and hydrogenating the resulting aldehyde to form a saturated alcohol.
The propene, produced for example by a steam cracking plant, has to be purified before hydroformylation, and its cost as feedstock is increased as a result.
There accordingly remains a need for an alternative route to commercially useful organic molecules, and more especially one that is capable, if desired, of producing a single isomeric product or a preponderant proportion of one or two isomers.